Many existing technologies rely on synthetic materials such as fluorinated lipids, emulsions and crown ethers to generate the fluorine signal in NMR. These technologies are good sources of fluorine signaling, especially for quantitative tissue oxygenation measurements. However, the toxicities and uncertainty of breadth of function associated with these materials have hampered their use. There are also classes of 19F MRI contrast agents being developed that harbor “smart” stimuli responsive capabilities to sense the appearance of biomarkers of diseases or changes in pH, metal ion concentration and partial pressure of oxygen (pO2) (Yu et al., Curr Med Chem 2005, 2:819-848; Senanayake et al., Chem. Commun., 2007, 2923-2925; Prior et al., In Vivo Magnetic Resonance Spectroscopy III: In Vivo MR Spectroscopy: Potential and Limitations. Vol. 28. Springer-Verlag; Berlin: 1992. p. 101-130; Deutsch et al., Biophys. J 1989, 55:799-804, Griffiths et al., NMR Biomed 1999; 12:495-504; Metcalfe et al., Cell Calcium 1985; 6:183-195; Mehta et al., Bioconjugate Chemistry, 1994, 5:257-261; Mehta et al., Bioconjugate Chemistry, 1994, 5:257-261). However, these contrast agents, while providing imaging functionality, are not capable of assisting with drug delivery.